A Labour MP who has repeatedly claimed that up to 2,000 British men are fighting in Syria and Iraq has based his figures on rough estimates based on various demographics in the UK.

The estimates by Khalid Mahmood, MP for Perry Barr, are four times higher than official figures for the number of Britons fighting in the region, which are between 400 and 500. The Home Office said it stands by the lower figures.

Mahmood told BBC News on Tuesday his estimates are based on general demographics in the UK. He said: “If you want to define that, you can look at the British Syrian community, the Kurdish community that’s here, then you look at the South East Asian heritage community here and the North and East African community here and a fair group of those young people have gone from here.”

He added that Brits had been travelling to fight in Iraq and Syria over the last three years. “If you just break it down to at least 500 per year, then you easily reach that.”

The Labour MP said this was a “conservative” estimate and returning Brits could result in a “significant” risk to the UK in the future.

But the estimates by Mahmood are at odds with a statement given by Foreign Minister William Hague in the House of Commons.

Hague said: “As I have previously told this House, we estimate the number of UK-linked individuals fighting in Syria to include approximately 400 British nationals and other UK-linked individuals who could present a particular risk should they return to the UK.”

Mahmood’s office was contacted multiple times by BuzzFeed and did not provide any sources for his figures by the time of publication.

A spokesperson for the Labour Party said it did not know where the MP got his figures and referred all questions to his office.